Method of producing dies from a preformed die part anchored in and projecting from a powdered metal die body



United States Patent @filice 3,M5,8l Patented July 31, 1962 METHOD OF PRGDUCING DES FRGM A PRE- FORIVED DE PART ANCHURED IN AND PRO- FROM A POWDERED METAL DIE Louis H. Morin, 12S Beechwood Ave, Bronx, N.Y.

Filed July 30, 1959, Ser. No. 836,568 4 Claims. ((31. 76-107) This invention relates to dies produced in accordance with the powder metallurgy process, wherein extremely fine grains of powdered metal are highly compressed upon a forming hob in production of one part of a die. More particularly, the invention deals with a method of this type and kind, wherein a preformed die portion such, for example, as a core plug is supported on the hob and, around which, the powdered metal of the die is compressed in securing the core plug in the die, with part of the plug protruding therefrom to form a cored portion in the resulting end product.

Still more particularly, the invention deals with the production of dies for use in forming scoops of separable fastener stringers, wherein the scoops are molded or cast from various materials including thermoplastic materials such, for example, as Delrin.

The novel features of the invention will be best understood from the following description, when taken together with the accompanying drawing, in which certain embodiments of theinvention are disclosed and, in which, the separate parts are designated by suitable reference characters in each of the views and, in which:

FIG. 1 is a diagrammatic perspective view of one corner portion of a hob illustrating one of the core plugs supported thereon, preparatory to utilizing the hob in forming a powdered metal die.

FIG. 2 is a sectional view through the hob substantially on the line 2'-2 of FIG. 1, diagrammatically illustrating the formation of a powdered metal die on the hob and within a sleeve or casing.

FIG. 3 is a sectional detail view, similar to FIG. 2, diagrammatically illustrating the formation of the companion die part used in' conjunction with the part illustrated in FIG. 2 in forming the resulting end product; and

FIG. 4 is a perspective view of a scoop detached with respect to its supporting stringer and illustrating the upper and lower east portions of the scoop formed by the dies indicated, at least, in part in FIGS. 2 and 3 of the drawing.

In illustrating one adaptation and use of my invention, I have diagrammatically illustrated in FIG. 4 of the drawing, detached with respect to its usual stringer support,

one scoop of a series of scoops and, for illustrative purposes, 11 can represent the upper half part of the scoop and 12 can represent the lower half part, the scoop being generally of the center ledge-type, now well known in the art. The portions 13 and 14 of the scoop 10 constitute the mounting end portions thereof and adjacent surfaces of these portions are fashioned to form a rounded bead receiving passage 15 and a narrow tape receiving passage 16.

The portions 13 and 14 also have vertically alined apertures or holes, diagrammatically seen at 17 and 18,

' through which stitchings are adapted to pass in attachment of cover tapes or the like to the scoops and also in reinforcing attachment of the scoops to the stringer tape.

. In order to economically produce products of the type and kind under consideration, it is desirable to form the dies for casting the products by powder metallurgy. However, it is diflicult, if not impossible, to form die parts of the character described which would produce core means in the resulting die part to produce holes, as at 17 and 18 in the resulting end product.

In order to solve this problem, the hob 19 for forming the die part is engraved to reproduce, for example, the upper part 11 of the resulting casting, as indicated at 11' in FIG. 1 of the drawing and also shown in section in FIG. 2. 11 includes a preformed hole 17', in which a preformed die part, in the form of a core plug 26), is supported. The plug 20 includes a tapered portion 21 which conforms accurately to the contour of the aperture or hole 17. Extending from the portion 21 is a cylindrical part 22., having an annular groove 23 therein to establish a key or anchorage of the plug 20 in the resulting powdered metal die 24. The inner end of the cylindrical portion 22 includes a radial rib or key portion 25, which will key the plug 21) against rotation within the die 24.

It will be noted, from a consideration of FIG. 1 of the drawing, that one complete engraved scoop half 11 is illustrated on the hob and at 11 is indicated part of an adjacent scoop form, it being understood, in this connection, that the hob may contain any desired number of these scoop forms for simultaneously producing in the die, as at 24 in FIG. 2, a corresponding number of impressions to form any desired increment of scoops which can be simultaneously cast upon a stringer tape in accordance with methods well known in the art.

In the production of certain types and kinds of products, a single engraved cavity forming impression can be produced on the hob in forming a single cavity in the resulting die.

Considering FIG. 2 of the drawing, 26 represents a sleeve or casing, in which the hob 19 is arranged with the core plug 29 supported thereon; whereupon, a measured quantity of powdered metal is arranged upon the hob 19 within the casing 25; whereupon, a plunger or punch 27 is moved downwardly under high pressure for compressing the powdered metal into a solid die body, as at 24 in FIG. 2 of the drawing.

Alloy steel powders are hydraulically pressed at approximately 128,000 pounds per square inch; whereas, other types of metals which can be used in forming dies can be compressed at lower pressures.

It will be apparent, from a consideration of FIG. 2 of the drawing, that the resulting formed die 24 will include, as an integral part thereof, the plug 26 securely anchored in the die, with the tapered core portion 21 only protruding beyond the surface 23 of the die. 29 represents the cavity of the die which would produce the upper part 11 of the resulting cast product, as noted in FIG. 4 of the drawing.

The method of producing the lower half 12 of the product 16* is diagrammatically illustrated, in part, in FIG. 3 of the drawing, in which figure 29 represents the cavity forming the lower part 12 and 21' represents the core pin of the core plug 29', again generally similar to the plug 21 of FIG. 2 of the drawing. The tapered portion 21 forms, as will be apparent, the aperture 18 in the lower part '12 of the product 10; whereas, the core portion 21 forms the aperture 17 in the upper part 11 of the product. In FIG. 3 of the drawing, 24' represents the die which, aside from the contour of the cavity 29', is generally similar to the die 24 of FIG. 2 of the drawing. 26' also illustrates part of the casing, in which the die is formed.

As is generally known in the art, after the dies 24, 24 have been produced in accordance with the teachings in FIGS. 2 and 3 of the drawing, the dies are sintered and hardened and otherwise treated in producing the resulting finished dies suitable for use in producing the east end products therefrom.

In insuring support of the core plugs 21) upon the hob 19, either the hob or the plugs can be magnetized to positively retain position of the plugs on the hob while, at the same time, facilitating withdrawal of the plugs from the hobs, after the plugs have been securely anchored in the powdered metal die. In connection with this anchorage phase, it will be understood that, while the key means, as at 23 and 25, are disclosed, such means is not essential, as the forming of the powdered metal around the plugs is such as to actually fuse the plugs in position to become as an integral part of the die.

Having fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. The method of producing powdered metal dies including a preformed die part, which consists in shaping a hob for producing the desired form of the cavity in the powdered metal die to be formed, supporting on the hob a preformed die part, magnetically retaining the preformed die part on the hob, preparatory to shaping the powdered metal on the hob and around said die part, forming on said preformed die part mezuis engaged by the powdered metal of the dye to key said die part against rotation in the powdered metal die, then compacting powdered metal under high pressure upon the hob and around said die part in forming the resulting die with said preformed die part secured thereto and includin a portion protruding into the cavity of the die, and then hardening and otherwise finishing the powdered metal die.

2. The method of producing powdered met-a1 dies including a preformed die part, which consists in shaping a hob for producing the desired form of the cavity in the powdered metal die to be formed, supporting on the hob a preformed die part, forming on said preformed die part means engaged by the powdered metal of the die to key said die part against rotation in the powdered metal die, then compacting powdered metal under high pressure upon the hob and around said die part in forming the resulting die with said preformed die part secured thereto and including a portion protruding into the cavity of the die, and then hardening and otherwise finishing the powdered metal die.

3. The method of producing powdered metal dies for use in forming scoops of separable fastener stringers, which consists in first producing engraved hobs defining the contour of upper and lower half portions of scoops to be formed, supporting plugs in apertured portions of the said upper and lower halves, shaping that part of the plugs embedded within the powdered metal dies to key the plugs against relative movement with respect to the dies, then pressure forming powdered metal onto the hobs and around said plugs to form powdered metal dies including, as an integral part thereof, said plugs, with portions of the plugs protruding from surfaces of the dies, and then hardening and otherwise finishing the dies preparatory to their use in forming scoops including vertically alined apertures in portions thereof.

4. The method of producing powdered metal dies for use in forming scoops of separable fastener stringers, which consists in first producing engraved hobs defining the contour of upper and lower half portions of scoops to be formed, supporting plugs in apertured portions of the said upper and lower halves, magnetically retaining the plugs on the hobs shaping that part of the plugs embedded within the powdered metal dies to key the plugs against relative movement with respect to the dies, then pressure forming powdered metal onto the hobs and around said plugs to form powdered metal dies including, as an integral part thereof, said plugs, with portions of the plugs protruding from surfaces of the dies, and then hardening and otherwise finishing the dies, preparatory to their use in forming scoops including vertically alined apertures in portions thereof.

References Cited in the file of this patent UNITED STATES PATENTS 

